Temperature-dependent optical properties of GaSe layered single crystals


IŞIK M., TUĞAY E., Gasanly N. M.

PHILOSOPHICAL MAGAZINE, cilt.96, ss.2564-2573, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 96 Konu: 24
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1080/14786435.2016.1209593
  • Dergi Adı: PHILOSOPHICAL MAGAZINE
  • Sayfa Sayıları: ss.2564-2573

Özet

Optical properties of GaSe single crystals have been investigated using temperature-dependent transmission and room temperature reflection measurements in the wavelength range of 380-1100nm. The analysis of the absorption data at room temperature showed the existence of indirect transitions in the crystal with energy band gap of 1.98eV. Temperature dependence of the transmission measurements revealed the shift of the absorption edge toward lower energy as temperature is increased from 10 to 280K. The rate of change of the indirect band gap was found as =-6.6x10(-4)eV/K from the analysis of experimental data under the light of theoretical relation giving the band gap energy as a function of temperature. The absolute zero value of the band gap energy and Debye temperature were calculated from the same analysis. The Wemple-DiDomenico single-effective-oscillator model applied to refractive index dispersion data was used to determine the oscillator energy, dispersion energy, oscillator strength and zero-frequency refractive index values.